建立图书馆网是我区图书馆事业当前发展的主要方向

我区图书馆事业如何深化改革，如何发展，这是我区图书馆界急需研究的重要课题。要发展，发展方向的选择很有必要，这形同飞机飞行要看准航线。选准了符合我区图书馆事业当前发展的实际方向，并在这个方向上开展工作则事半功倍。     

机器苍蝇

研究人员正采用最先进的技术。开发一种机器苍蝇，它能深入敌后收集情报或提供监测空气质量及对花进行授粉的服务。     

基于有限时间控制的高超声速飞行器控制律设计

针对高超声速飞行器的飞行控制问题,提出了一种基于有限时间控制技术的控制方法.根据高超声速飞行器纵向模型的特点,将高度控制和速度控制看作2个子系统分别设计控制器.采用非线性动态逆与有限时间控制技术相结合的方法,分别设计了速度控制器和高度控制器.速度控制器设计时考虑了发动机的动态,使得飞行速度在有限时间内收敛到给定值.飞行...     

鱿鱼也飞翔

俗话说:"海阔凭鱼跃,天高任鸟飞。"其实,不但有海鸟能潜入海中数分钟捕鱼,一些海洋动物也能飞到空中避祸,飞鱼就是人们所熟悉的会飞的海洋动物。飞鱼科的鱼儿有40多种,它们的共同特征都是胸鳍特别发达,像鸟类的翅膀一样。长长的胸鳍一直延伸到尾部,整个身体像织布的"长梭"。它凭借自己流线型的优美体型,在海中以每秒     

长途飞行应提防静脉血栓

在经过10小时的飞行后,一名62岁德国籍男子在抵达机场后经过机场通道时,突发疾病猝死。医务人员初步判断,该男子可能因长途飞行中久坐不动,导致下飞机时出现了被称为“经济舱综合征”的肺栓塞而引发意外。但也许很多人并不知道,肺栓塞正是静脉血栓中最严重的一种疾病表现,起病急并可能在发病两小时内夺命,从而酿发意外惨剧。     

Uptake kinetics of 3-buten-1-ol, 4-penten-1-ol and 3-methyl-3-buten-1-ol into sulfuric acid solutions

Unsaturated alcohols are important components in complex mixtures of oxygenated volatile organic compounds, and play a significant role in atmospheric chemistry. The uptake kinetics of 3-buten-1-ol (BO31), 4-penten-1-ol (PO41) and 3-methyl-3-buten-1-ol (MBO331) into 20 wt%-80 wt% H₂SO₄ solutions were studied, using a rotated wetted-wall reactor coupled to a differentially pumped single-photon ionization time of flight mass spectrometer (SPI-TOFMS). With increasing acidity, the uptake processes changed from reversible to irreversible (reactive). Reactive uptake was observed in 60 wt%-80 wt%, 50 wt%-80 wt% and 30 wt%-80 wt% H₂SO₄ solutions for BO31, PO41 and MBO331, respectively. Reactive uptake coefficients were acquired and are reported here for the first time. Reactivity order followed the trend: BO31<PO41<MBO331. An electrophilic addition mechanism of H₂SO₄ to the C=C double bond was used to explain this trend. Atmospheric implications were discussed, based on the reactive uptake coefficients. This heterogeneous reaction with sulfuric acid aerosols may be a potential degradation pathway of unsaturated alcohols, and should not be neglected.     

Comparative proteomics analysis of <Emphasis Type="Italic">OsNAS1</Emphasis> transgenic <Emphasis Type="Italic">Brassica napus</Emphasis> under salt stress

Salt stress is one of the major abiotic stresses in agricultural plants worldwide. We used proteomics to analyze the differential expression of proteins in transgenic OsNAS1 and non-transformant Brassica napus treated with 20 mmol/L Na₂CO₃. Total protein from the leaves was extracted and separated through a high-resolution and highly repetitive two-dimensional electrophoresis (2-DE) technology system. Twelve protein spots were reproducibly observed to be upregulated by more than 2-fold between transgenic and non-transformant B. napus. These 12 spots were digested in-gel with trypsin and characterized by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to obtain the peptide mass fingerprints. Protein database searching revealed that 5 of these proteins are involved in salt tolerance: dehydrogenase, glutathione S-transferase, peroxidase, 20S proteasome beta subunit, and ribulose-1,5-bisphosphate carboxylase/oxygenase. The potential functions of these identified proteins in substance and energy metabolism, stress tolerance, protein degradation, and cell defense are discussed. The salt tolerance of the transgenic rapeseed was significantly improved by the introduction of the OsNAS1 gene from Brazilian upland rice of Oryza sativa (cv. IAPAR 9).     

飞参数据应用浅析

根据飞机试飞、机务维修保障的特点以及飞行训练的特殊性,利用飞参系统记录数据的客观性,提出飞参数据在辅助机务维修保障、飞行训练质量评估和改进飞机的飞行性能等领域的应用。     

小型无人搜救飞艇的控制系统设计研究

本文介绍了一套小型无人搜救飞艇的飞行控制系统设计,硬件部分实现了以MCU为核心的传感器模块、无线通信模块、驱动器模块等电路设计,软件部分则采用模块化设计方法,按照不同功能将软件系统划分为不同子模块,并分别对各个子模块进行软件设计。该控制系统具有自主性强、鲁棒性高、通信实时性好等优点,能够一定程度上提高无人搜救飞艇的性能。     

浅谈通用航空飞机飞行记录单的编制

安全和效率是航空业永恒的目标,随着通用航空事业的发展,越来越多的公司进入这个充满挑战的行业,赢利是这些公司不变的追求,飞行记录单使安全、效率、赢利在飞机使用维护中达到和谐统一。航空运营是个复杂的系统,本文根据实际工作经验,浅析了飞行记录单的编制方法,为通航运营人编制适合自身的飞行记录单提供了指导。